JP5530699B2 - Leather-like sheet laminate - Google Patents

Description

The present invention relates to a leather-like sheet-like laminate capable of molding bags, school bags, cases and the like by heat molding.

Conventionally, natural leather and artificial leather have been used for bags, school bags, etc., but their production requires complex processes for compounding and molding of the materials, and the product is used to prevent its shape loss. It was heavy due to the use of plates.
For example, for case types such as attache case, the hard type is made of ABS resin sheet and the soft type is made of pef (polyolefin foam), etc., but the weight is heavy and the appearance is poor. It becomes a thing.
Also, mix low-melting polyester fibers with ordinary polyester fibers, heat-treat them to melt the low-melting polyester fibers, and then combine the synthetic leather and other appropriate materials with the core to be pressed, and then heat A molding method is known (see Patent Document 1).

JP-A-2-41227

In the invention described in Patent Document 1, the non-woven fabric mixed with the heat-sealing fibers is preliminarily heated and then thermoformed. However, the stretch at the time of molding is insufficient, and the resulting core material is thick. The weight was also heavy.
An object of the present invention is to provide a leather-like sheet-like laminate that eliminates these defects, is thin and lightweight, has high strength, and is excellent in thermoformability. Moreover, the objective of this invention is providing the leather-like sheet-like laminated body which has a favorable external appearance and can manufacture the molded object excellent in rigidity.

The above object state, and are difference 30 ° C. over a core portion resin melting point and the sheath of the resin melting point, or less core resin melting point of 230 ° C., sheath resin melting point Ru der 260 ° C. or higher sheath structure This is achieved by a leather-like sheet-like laminate in which a woven or knitted fabric made of fibers and a skin material are laminated via an adhesive layer.

In the present invention, it is preferable that the core resin is isophthalic acid copolymer polyester and the sheath resin is homopolyethylene terephthalate.

The present invention provides a leather-like sheet-like laminate that is thin and lightweight, has high strength, and is excellent in thermoformability. Moreover, the molded object which shape | molded the leather-like sheet-like laminated body of this invention has a favorable external appearance, and was excellent in durability and a shape retention property.

The leather-like sheet-like laminate of the present invention is suitably used for furniture such as shoes, cushions, sofas, automobile interior materials, trays, etc., in addition to bags, school bags, cases, and the like.

  The core-sheath structure fiber used in the present invention needs to have a difference of 30 ° C. or more between the core resin melting point and the sheath resin melting point. Here, when using amorphous resin for a core part or a sheath part, a softening point is adopted instead of a melting point.

The melting point means a crystal melting temperature in DSC measurement of a thermoplastic resin having crystallinity, and the softening point means a temperature at which the resin constituting the fiber starts to soften.
In the present invention, the melting point is measured using a differential scanning calorimeter (DSC7 manufactured by Perkin Elmer Co.) at a heating rate of 20 ° C./min. On the other hand, the softening point is measured in accordance with “Method of softening temperature test by thermomechanical analysis of thermoplastic film and sheet” of JIS K7196 method.

The core-sheath fiber used in the present invention is, for example, a resin whose core resin has a resin melting point of 230 ° C. or lower, such as low-melting polyester, and a resin whose sheath resin has a resin melting point of 260 ° C. or higher, such as a homopolymer. It may be made of polyethylene terephthalate. As the low melting point polyester, for example, copolymerized polyethylene terephthalate obtained by copolymerizing isophthalic acid is used. In addition, a copolymerized polyester obtained by copolymerizing 15 to 40 mol% of isophthalic acid with polyethylene terephthalate becomes amorphous, and therefore has a softening point of 130 to 230 ° C.

The sheath resin may be polyethylene terephthalate copolymerized with 10 mol% or less of isophthalic acid instead of homopolyethylene terephthalate.
When such a core-sheath structure fiber using a resin having a lower melting point than the sheath is used for the core, a relatively soft leather-like sheet-like laminate can be obtained.

The composite ratio (volume ratio) of the core-sheath resin is preferably 20: 1 to 3: 1. If the volume of the core portion is large, the core-sheath structure may not be maintained, and if the volume of the sheath portion is large, moldability may be deteriorated.

The fineness of the core-sheath structure fiber used in the present invention is preferably 30 to 330 dtex. If it is less than 30 dtex, the strength tends to be low, and if it exceeds 330 dtex, the moldability tends to deteriorate. More preferably, it is 50-300 dtex. Moreover, what is necessary is just to set the structure number of a core sheath structure fiber suitably.

The core-sheath structure fiber used in the present invention can be produced by a normal spinning device.
Moreover, it is preferable that the core-sheath structure fiber used by this invention is not eccentric, and there may be two or more core parts, and a part of core part may be exposed to the fiber surface.

Moreover, the core-sheath structure fiber used by this invention is good also as what combined suitably the polyester-type resin, the polyamide-type resin, the polyolefin-type resin other than the combination of the said resin.

The woven fabric composed of the core-sheath structure fibers as described above may be woven using a normal loom, and the woven structure may be set as appropriate, preferably plain weave. The mixing ratio of the core-sheath structure fiber is preferably 40% or more. When the mixing ratio is less than 40%, the retaining property when formed into a molded product tends to deteriorate.
The fiber used together with the core-sheath structure fiber may be a natural fiber or a synthetic fiber.

Further, the knitted fabric made of the core-sheath structure fiber may be knitted using a normal knitting machine, and may be warp knitted or circular knitted.
The mixing ratio of the core-sheath structure fiber is preferably 40% or more. When the mixing ratio is less than 40%, the retaining property when formed into a molded product tends to deteriorate.

INDUSTRIAL APPLICABILITY The present invention can provide a leather-like sheet-like laminate having excellent moldability while maintaining strength by using a core-sheath structure fiber made of a resin having a melting point difference as described above. In addition, the present invention can uniformly form a leather-like sheet-like laminate by using a woven or knitted fabric composed of the above-described core-sheath structure fibers, and the molded article after molding is less distorted. .

The adhesive constituting the leather-like sheet-like laminate of the present invention is a polyurethane resin, acrylic resin, silicone resin, polyvinyl alcohol resin, nylon resin, polyester resin, fluorine resin, polyethylene resin, Polypropylene resins, polyvinyl chloride resins and the like can be used arbitrarily, but preferably polyurethane resins, particularly preferably polycarbonate polyurethane resins.

The thickness of the adhesive layer is preferably 10 to 250 μm from the viewpoint of adhesiveness and texture. If the thickness is less than 10 μm, sufficient adhesiveness tends to be not obtained, and if it exceeds 250 μm, the texture is hard and it tends to be difficult to obtain a molded product having an acute curve.
The solid content and viscosity of the adhesive resin may be any as long as they can be produced.

Examples of the resin used for the skin material constituting the leather-like sheet-like laminate of the present invention include polyurethane, polyvinyl chloride (PVC), polypropylene (PP), polyethylene (PE), polyamide, and the like. Among them, polyurethane is preferable. . This polyurethane is obtained from, for example, a low melting point polyol having a molecular weight of 500 to 6000, an organic diisocyanate, and a chain extender having a molecular weight of 500 or less. As the polyol, an aliphatic polycarbonate diol having a molecular weight of 500 to 5,000 is preferable. Examples of the organic diisocyanate include diphenylmethane diisocyanate, tolylene diisocyanate, isophorone diisocyanate, hydroxylated diphenylmethane diisocyanate, xylene diisocyanate, 2.6-diisocyanate methylcaproate, hexanetyrene diisocyanate, and the like. Examples of the chain extender having a molecular weight of 500 or less include glycol, amino alcohol, or triol.

The production method for obtaining the skin material is not particularly limited, and can be performed using a roll coater, a knife overcoater or the like. It is also possible to stack by applying a plurality of times. Examples of the organic solvent used for dissolving the resin include dimethylformamide, diethylformamide, diethyl sulfoxide, methyl ethyl ketone dioxane, cyclohexane, toluene, and a mixture of two or more thereof.

  As for the thickness of the skin material used for this invention, 10-200 micrometers is preferable, More preferably, it is 15-150 micrometers. If it is less than 10 μm, a problem of hole formation may occur, and if it exceeds 200 μm, the epidermis tends to be too hard.

The base material, adhesive, and skin material used in the present invention may contain various additives usually used for resins. Such additives include, for example, thickeners, curing agents, crosslinking agents, pigments, gloss imparting agents, light stabilizers, antioxidants, ultraviolet absorbers, antibacterial agents, flame retardants, antistatic agents and the like.

The leather-like sheet-like laminate of the present invention preferably has a strength of 120 to 300 N / 3 cm and an elongation of 10 to 80%. When the strength is lower than 120 N / 3 cm, it tends to be less practical, and when it is higher than 300 N / 3 cm, it becomes hard and tends to cause a problem in moldability. Further, if the elongation is lower than 10%, there is a tendency that a problem occurs in moldability, and if it exceeds 80%, the woven or knitted structure may be broken.
Moreover, the thickness of the leather-like sheet-like laminate of the present invention can be about 0.3 to 1.0 mm. When the leather-like sheet-like laminate is too thin, the strength is lowered, which may cause problems in practical use. On the other hand, when the leather-like laminate is too thick, the moldability tends to deteriorate.

The leather-like sheet-like lamination of the present invention is, for example, by applying an adhesive to the skin material formed on the release paper, and laminating the woven or knitted fabric as a base material thereon, and pressing with a roller, It is obtained by heat treatment and peeling off the release paper.

Thermoforming of the leather-like sheet-like laminate of the present invention is performed by shaping or shaping into a desired product shape by a method such as a combination of high-frequency heating, electric heating or steam heating and vacuum molding, compressed air molding or hot plate molding. Join. Molding conditions such as temperature and pressure may be appropriately set depending on the constituent material, thickness, and shaping shape of the leather-like sheet-like laminate.
The leather-like sheet-like laminate of the present invention is sufficiently stretched at the time of molding, can be molded with an acute curve, is not easily wrinkled, and has excellent moldability. Moreover, since it is possible to mold at a temperature lower than the melting point of the resin used for the skin material, the surface of the skin material is not damaged by the molding process.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited to this Example. In addition, the evaluation in an Example measured by the method shown below.

Strength and elongation: The base fabric was measured according to JIS L1906. A test piece having a width of 25 mm and a length of 200 mm was collected, and using a tensile tester (Orientec), the distance between the chucks was set to 100 mm and the test piece was fixed. The sample was stretched at a tensile speed of 300 mm / min, and the strength (25 mm width) and elongation when the test piece was broken were measured.
Further, the leather-like sheet-like laminate was measured according to JIS K6772. A test piece having a width of 30 mm and a length of 250 mm is collected, and a mark line with a distance of 100 mm is attached to the center of the test piece. The test piece is attached to a tensile tester, pulled at a gripping interval of 150 mm and a pulling speed of 200 m / min, measured the maximum load and the distance between marked lines when either the test piece coating or the base fabric is cut, and the strength (30 mm Width) and elongation were measured.

  Thickness: Measured according to JIS L-1098. Measuring instrument: Constant pressure thickness measuring instrument TYPE PF-11 (manufactured by Rough Rock).

Moldability: A mold was set, the oven temperature was set to an appropriate temperature condition for each material, heated for 2 minutes, and then allowed to stand at room temperature for 1 hour. Thereafter, the moldability was evaluated visually for the presence or absence of wrinkles and the shape disorder of the corner portion.

Mold holding property: After molding, it was left at room temperature for 24 hours, and it was confirmed whether it was out of shape.

(Example 1 )
Regular warp yarn (56 dtex / 24f, strength 4.5 cN / dtex, elongation 3.5%) is used as the warp yarn, and isophthalic acid copolymer polyester (isophthalic acid ratio 20 mol%) (softening point 185 ° C.) as the weft yarn. Core-sheath structure fiber (56 dtex / 24f, strength 4.3 cN / dtex, elongation 38%) with a composite ratio of core-sheath of 1: 1 using homopolyester (melting point 260 ° C.) for the core Was used to weave a taffeta having a warp density of 103 / inch (2.54 cm), a weft density of 100 / inch (2.54 cm), and a width of 123 cm. It processed at 160 degreeC for 1 minute using the pin tenter type | mold heat setter, and finished it in width 123cm. This taffeta had a thickness of 0.09 mm, a strength of 255 N / 2.5 cm, and an elongation of 46%.

Subsequently, 100 parts by weight of C-4010 (manufactured by DIC Corporation), 8 parts by weight of Coronate L (manufactured by Nippon Polyurethane Industry Co., Ltd.) on a skin material made of a dry polycarbonate polyurethane film having a thickness of 30 μm adhered to the release paper 85 g / m of urethane adhesive consisting of 5 parts by weight, Accel S (manufactured by DIC Corporation) and 40 parts by weight (20/20 parts by weight) of solvent (methyl ethyl ketone / toluene) ² Apply, then dry continuously at 80 ° C. to remove the solvent, then overlay the fabric, nip with a pressure roller and press the adhesive into the fabric appropriately, then heat treated at 60 ° C. for 24 hours, Finally, the release paper was peeled off to obtain a leather-like sheet-like laminate.

(Comparative Example 1)
A leather-like sheet-like laminate was obtained in the same manner as in Example 1 except that taffeta using 100% regular polyester fiber of 56 dtex / 24f was used.

Strength of the leather-like sheet laminate of Example 1及 beauty Comparative Example 1 were measured elongation and thickness. The results are also shown in Table 1.
Further, the moldability of the leather-like sheet laminate of Example 1及 beauty Comparative Example 1 as in Table 2, also the molded retention was confirmed as shown in Table 3.

The leather-like sheet-like laminate of Example 1 had good moldability and mold retention. However, the leather-like sheet-like laminate of Comparative Example 1 could not be molded at the same molding temperature as in the examples.

Claims (2)

Ri der difference is 30 ° C. or more and core resin melting point and a sheath portion melting point of the resin, and a core resin melting point of 230 ° C. or less, knitted woven sheath melting point of the resin is composed of Der Ru core-sheath structure fibers 260 ° C. or higher And a leather-like sheet-like laminate in which a skin material is laminated via an adhesive layer. The leather-like sheet-like laminate according to claim 1, wherein the core resin is isophthalic acid copolymer polyester and the sheath resin is homopolyethylene terephthalate .